Before Monroe hit it big, she was (as many aspiring actresses are) in need of cash. In 1949, she posed nude for photographer Tom Kelley in exchange for fifty dollars. Kelley sold his photographs of Monroe to Western Lithograph Company, which made calendars.

Only a year later, things turned around for the actress when her career finally began to take flight. In 1950, Monroe appeared in two films, "Asphalt Jungle," and "All About Eve," and the starlet finally began to gain recognition.

Four years later, Monroe's images resurfaced when Hefner purchased Kelley's photographs of Monroe with "nothing but the radio on" from the Chicago calendar maker for $500, according to the LA Times. Hefner made Monroe his first ever centerfold, or "Sweetheart of the Month," as it was called at the time. (Hefner didn't come up with his idea for "Playmate of the month" until about a year after the magazine's launch.)

After the publication, Monroe made the decision to do an interview in which she explained that she had been desperate for money when she posed for the nude photos. And it didn't seem to negatively affect her career at all. She also developed a close relationship with Hefner.

Strangely enough, Hefner will be laid to rest beside Marilyn Monroe in Westwood Village Memorial Park, located in Los Angeles, California. He bought the crypt next to Monroe's for $75,000 in 1992, according to The Guardian.